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31.
Carlos E. Da Costa Joo V. Comasseto Iracema H.-S. Crusius Leandro H. Andrade Andr L.M. Porto 《Journal of Molecular Catalysis .B, Enzymatic》2007,45(3-4):135-139
Aspergillus terreus CCT 3320 and A. terreus URM 3571 catalysed the biotransformations of organic β-hydroxyphenyl selenides through oxidation and methylation reactions. The kinetic resolution of (RS)-1-(phenylseleno)-2-propanol (1) via enantioselective oxidation produced (+)-(S)-1 in high enantiomeric excess (>99%) and in a yield of 50% as determined by product isolation. Oxidation of the R-enantiomer of 1, followed by elimination of the propyl moiety and subsequent methylation of the presumed intermediate, led to the formation of methylphenyl-selenide, which was isolated in a yield of 40%. Whole cells of A. terreus also biocatalysed transformations of diphenyldiselenide, benzeneseleninic acid, (RS)-1-(phenylseleno)-2-pentanol and (RS)-1-(phenylseleno)-3-methyl-2-butanol, but not of (RS)-1-(phenylseleno)-2-phenyl-methanol. This is the first report of the biomethylation of organoselenium compounds by whole cells of A. terreus. 相似文献
32.
Ana Francisco Miguel Porto Lia Ascensão 《Botanical journal of the Linnean Society. Linnean Society of London》2015,179(3):454-476
Reconstructing the phylogeny of the sexually deceptive orchid genus Ophrys is crucial to our understanding of the evolution of its complex floral morphology. Molecular phylogenetic analyses showed that section Pseudophrys forms a well supported clade with Ophrys bombyliflora, O. tenthredinifera and O. speculum, but were unable to elucidate the relationships between these four groups of taxa. Here we conduct a morphological phylogenetic analysis of this unresolved clade of Ophrys based on a data matrix of 45 macro‐ and micromorphological and anatomical floral characters, using maximum parsimony and Bayesian inference. Our cladistic analysis yielded a single most parsimonious tree and a Bayesian 50% majority‐rule consensus tree which differed in their overall topology but agreed that O. tenthredinifera and O. bombyliflora are not sister groups. The phylogenetic placement of O. tenthredinifera was ambiguous since it shares six valid synapomorphies each with the cluster of O. speculum–O. bombyliflora and with section Pseudophrys. In contrast, O. bombyliflora is most likely the sister group to O. speculum, a finding that rejects an earlier morphological phylogenetic hypothesis and favours the existing molecular trees based on nuclear ITS rather than plastid data. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 454–476. 相似文献
33.
Mariele Porto Carneiro Le?o Patricia Vieira Tiago Fernando Dini Andreote Welington Luiz de Araújo Neiva Tinti de Oliveira 《Genetics and molecular biology》2015,38(1):86-92
The entomopathogenic fungi of the genus Metarhizium have several
subtilisin-like proteases that are involved in pathogenesis and these have been used
to investigate genes that are differentially expressed in response to different
growth conditions. The identification and characterization of these proteases can
provide insight into how the fungus is capable of infecting a wide variety of insects
and adapt to different substrates. In addition, the pr1A gene has
been used for the genetic improvement of strains used in pest control. In this study
we used quantitative RT-PCR to assess the relative expression levels of the
pr1A gene in M. anisopliae and M.
acridum during growth in different culture conditions and during
infection of the sugar cane borer, Diatraea saccharalis Fabricius.
We also carried out a pathogenicity test to assess the virulence of both species
against D. saccharalis and correlated the results with the pattern
of pr1A gene expression. This analysis revealed that, in both
species, the pr1A gene was differentially expressed under the growth
conditions studied and during the pathogenic process. M. anisopliae
showed higher expression of pr1A in all conditions examined, when
compared to M. acridum. Furthermore, M. anisopliae
showed a greater potential to control D. saccharalis. Taken
together, our results suggest that these species have developed different strategies
to adapt to different growing conditions. 相似文献
34.
Mechanical clearing of understory vegetation is increasingly used in Euro-Mediterranean forests to reduce fire hazard, yet
its long-term consequences for biodiversity remain poorly understood. This study analysed the influence of time since understory
management and management frequency, on herbaceous species richness, cover and composition, functional richness and composition,
and richness and cover within functional groups (life and growth forms, dispersal strategy, clonality, and plant height),
using a chronosequence of cork oak (Quercus suber) stands spanning about 70 years. Overall species richness was virtually constant over time, but the richness of species with
annual life form and plasticity in height was much higher in recently and recurrently treated stands; the opposite was found
for perennial (mainly hemicryptophytes and chamaephytes), tussock-forming and clonal species richness, and functional richness.
Overall herbaceous cover and that of annual, semi-basal, non-clonal and plastic species (in height) were favoured by recent
and recurrent fuel treatments; cover by perennial (hemicryptophytes and chamaephytes), short basal, tussock-forming, and clonal
species tended to increase for >10–20 years after management, and declined with management frequency. There was a marked shift
in species and functional composition associated with time since understory management and management frequency. These findings
suggest that widespread fuel management at <10 year intervals may shift understory herb communities to early-successional
stages, impairing the persistence of species and functional groups recovering slowly after disturbance. Fuel management needs
to balance the dual goals of fire hazard reduction and biodiversity conservation, retaining undisturbed patches in landscapes
otherwise managed to reduce fuel accumulation. 相似文献
35.
Scarlet Nere Ortega Marcia Nitschke Ana Maria Mouad Maria Diva Landgraf Maria Olímpia Oliveira Rezende Mirna Helena Regali Seleghim Lara Durães Sette André Luiz Meleiro Porto 《Biodegradation》2011,22(1):43-50
The fungi Aspergillus sydowii Ce15, Aspergillus sydowii Ce19, Aspergillus sydowii Gc12, Bionectria sp. Ce5, Penicillium miczynskii Gc5, Penicillium raistrickii Ce16 and Trichoderma sp. Gc1, isolated from marine sponges Geodia corticostylifera and Chelonaplysylla erecta, were evaluated for their ability to grow in the presence of DDD pesticide. Increasing concentrations of DDD pesticide, i.e.,
5.0 mg (1.56 × 10−12 mmol), 10.0 mg (3.12 × 10−2 mmol) and 15.0 mg (4.68 × 10−2 mmol) in solid and liquid culture media were tested. The fungi Trichoderma sp. Gc1 and Penicillium miczynskii Gc5 were able to grow in the presence of up to 15.0 mg of DDD, suggesting their potential for biodegradation. A 100% degradation
of DDD was attained in liquid culture medium when Trichoderma sp. Gc1 was previously cultivated for 5 days and supplemented with 5.0 mg of DDD in the presence of hydrogen peroxide. However,
the quantitative analysis showed that DDD was accumulated on mycelium and biodegradation level reached a maximum value of
58% after 14 days. 相似文献
36.
Fernanda Errero Porto Ana Luiza de Brito Portela-Castro Isabel Cristina Martins-Santos 《Ichthyological Research》2011,58(3):225-231
Cytogenetic analysis in three Rineloricaria pentamaculata populations revealed diploid number 2n = 56 chromosomes, karyotype formula 8m/sm + 48st/a and FN = 64. Owing to the presence of the heteromorphic chromosome pair
with a big submetacentric chromosome and a small acrocentric one in both males and females, 42.9% of specimens in the Tauá
Stream population had the karyotype formula 9m/sm + 47st/a and FN = 65. Analysis of the nucleolus-organizing region by Ag-NOR
and FISH techniques showed a single NOR system at pair 5 for R. pentamaculata populations of the Keller River and the Tauá Stream. However, specimens of populations of the Tatupeba Stream had multiple
NOR systems at pairs 5 and 8. A constitutive heterochromatin pattern in R. pentamaculata is mainly distributed in the pericentromeric and telomeric regions with interstitial markers in certain chromosomes. Heterochromatin
is located in the telomeric and centromeric positions of the acrocentric chromosome in the heteromorphic pair of the Tauá
Stream population. In the submetacentric chromosome the markings are located in the telomeric (short arm), pericentomeric
and interstitial (long arm) positions. The origins of polymorphisms are discussed. 相似文献
37.
Carolina A. Lima José L. Lima Filho Benício B. Neto Attilio Converti Maria G. Carneiro da Cunha Ana L. F. Porto 《Biotechnology and Bioprocess Engineering》2011,16(3):549-560
A 24 full factorial design was used to identify the main effects and interactions of the initial medium pH, soybean flour concentration,
temperature and orbital agitation speed on extracellular collagenase production by Penicillium aurantiogriseum URM4622. The most significant variables for collagenase production were soybean flour concentration and initial medium pH
that had positive main effects, and temperature that had a negative one. Protein concentration in soybean flour revealed to
be a significant factor for the production of a collagenase serine proteinase. The most favorable production conditions were
found to be 0.75% soybean flour, pH 8.0, 200 rpm, and 28°C, which led to a collagenase activity of 164 U. The enzyme showed
an optimum activity at 37°C and pH 9.0, was stable over wide ranges of pH and temperature (6.0 ∼ 10.0 and 25 ∼ 45°C, respectively)
and was strongly inhibited by 10 mM phenylmethylsulphonylfluoride. The firstorder rate constants for collagenase inactivation
in the crude extract, calculated from semi-log plots of the residual activity versus time, were used in Arrhenius and Eyring
plots to estimate the main thermodynamic parameters of thermoinactivation (E*
d
= 107.4 kJ/mol and ΔH*
d
= 104.7 kJ/mol). The enzyme is probably an extracellular neutral serine collagenase effective on azocoll, gelatin and collagen
decomposition. 相似文献
38.
We derive an analytic expression for site-specific stationary distributions of amino acids from the structurally constrained neutral (SCN) model of protein evolution with conservation of folding stability. The stationary distributions that we obtain have a Boltzmann-like shape, and their effective temperature parameter, measuring the limit of divergent evolutionary changes at a given site, can be predicted from a site-specific topological property, the principal eigenvector of the contact matrix of the native conformation of the protein. These analytic results, obtained without free parameters, are compared with simulations of the SCN model and with the site-specific amino acid distributions obtained from the Protein Data Bank. These results also provide new insights into how the topology of a protein fold influences its designability, i.e., the number of sequences compatible with that fold. The dependence of the effective temperature on the principal eigenvector decreases for longer proteins, as a possible consequence of the fact that selection for thermodynamic stability becomes weaker in this case. 相似文献
39.
40.
AB Chang NC Cox J Purcell JM Marchant PJ Lewindon GJ Cleghorn LC Ee GD Withers MK Patrick J Faoagali 《Respiratory research》2005,6(1):1-5